Emacs overlay usage - error: "attribute ... missing"

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1

I am introducing the emacs overlay to my configuration flake, but have run up against a problem with this error:

error: attribute 'emacsWithPackagesFromUsePackage' missing

       at /nix/store/hqrnx1kmyrgpjsslgc4c3fr0nyq24mk2-source/home/paul/features/emacs/default.nix:3:11:

            2| let
            3|   emacs = pkgs.emacsWithPackagesFromUsePackage {
             |           ^
            4|     package = pkgs.emacsUnstable;
(use '--show-trace' to show detailed location information)

I believe I have followed the instructions correctly to configure the overlay properly.

  • I have included the overlay as an input in my flake:
    emacs-overlay = {
      url = "github:nix-community/emacs-overlay";
    };
  • I have added the overlay to nixpkgs:
  nixpkgs = {
    overlays = ( builtins.attrValues outputs.overlays) ++ 
               [ inputs.emacs-overlay.overlay ];
    config = {
      allowUnfree = true;
    };
  };
  • I have called the missing function in my home manager emacs module:
{ pkgs, config, lib, ... }: 
let
  emacs = pkgs.emacsWithPackagesFromUsePackage {
    package = pkgs.emacsUnstable;
    config = ./init.el;
    extraEmacsPackages = epkgs: with epkgs; [
      use-package
    ];
    overrides = final: _prev: {
      nix-theme = final.callPackage ./theme.nix { inherit config; };
    };
    alwaysEnsure = true;
  };
in {
  home.packages = [ emacs ];
  home.file.".emacs.d/init.el".text = builtins.readFile ./init.el;
  home.file.".emacs.d/early-init.el".text = builtins.readFile ./early-init.el;
  home.file.".emacs.d/lisp/my-org-mode.el".text = builtins.readFile ./lisp/my-org-mode.el;

  services.emacs = {
    enable = true;
    client.enable = true;
    defaultEditor = lib.mkDefault true;
    socketActivation.enable = true;
  };
}

The full configuration is here. It is modeled on Misterio77’s config (Thanks Gabriel), but any errors are mine, not his!

I would love some pointers as to where to look for the problem.

Thanks in advance for reading and commenting!

2

Following some direction on matrix, this has now been resolved. My configuration is setup with home manager as a separate module. My addition of the overlay as an input above covers the system build, but not the home manager part - I needed to add the overlay to the home manager nixpkgs definition.